Question Exhaust Smell in Cab

[BIG JOE]

well, it's kind of hard to get fuel in the heater plenum without it being put there..

that's why I was thinking mold or fungus on the heater core..
there are various mold, mildew & fungus killers on the market designed for use in mobile AC systems..
check with your local parts store..

could even be a heater core starting to leak???

Good point.

Maybe a film, from fumes, has collected on some trapped condensate water.. only gets activated (stinks) by Heat ??

JR, you might [manually] drain the plenum area, by sticking a tube (straw) up thru the condensate drain tube on the bottom of the HAVC portion thats under the hood.. to make sure you don't have any liquids trapped it there. Then do like JLD sez: get some of that mold/mildew killer stuff.

Joe

 

[JRJ04]

Good point.

Maybe a film, from fumes, has collected on some trapped condensate water.. only gets activated (stinks) by Heat ??

JR, you might [manually] drain the plenum area, by sticking a tube (straw) up thru the condensate drain tube on the bottom of the HAVC portion thats under the hood.. to make sure you don't have any liquids trapped it there. Then do like JLD sez: get some of that mold/mildew killer stuff.

Joe

well we had a pretty good cold snap come through here, but once it warms up...im gonna give it all a good look over.

I'm thinking it just might be that the box isnt sealed tight and when its not on recirc im getting the fumes in there. im sure the donut gaskets arent sealed perfect anymore either, but i think injector o-rings will probably need to be done before i tackle that.

 

[BIG JOE]

well we had a pretty good cold snap come through here, but once it warms up...im gonna give it all a good look over. but i think injector o-rings will probably need to be done before i tackle that.

 

[rmwitt]

has anyone suggested fuel in the water? of course, when you turn on the heater the water/fuel mixture is running closer to the cab where you are sitting. take the radiator cap off to check for fuel in the water. i had this issue before. Turns out that i had a cracked injector cup. Had to replace the cup on all water hoses and plastic water resevior, etc.

 

[EmptyDub]

I had the same symptoms just a month or two ago... The truck ran fine- absolutely NO performance issues at all.

It was cold outside, so every morning when I'd turn the heater/defroster on, I could smell exhaust fumes really strong. As soon as I'd start moving the smell would go away- come to a stop and idle for a sec and I'd smell it again???

Long story short- I took it back to the dealer (I'd had the truck serviced just a few days before), and found that the tech didn't tighten up the oil filler cap! They said the back pressure from the engine was forcing fumes back through the filler tube and into the engine bay. The heater was sucking it up and blowing it into the cab. It would only do it when I was idling- the fumes would just pool under the hood.

I was terrified when they started talking about removing the cab in order to replace a possible cracked Y-tube, etc... turned out to be just a loose cap. Might check yours just in case if you haven't already- sometimes the simplest solution can be the toughest to diagnose!

Hope you get it figured out!

 

[JRJ04]

Thanks! Ill have to check that out...mine has had a crack in it for the longest, but i dont know if its enough to be pusing fumes out or not. nonetheless...ill check it out

 

[JRJ04]

I think I fixed it

Gooped some RTV sealant around it where i could and did a test...seems to be gone..we'll see how long it lasts.